1. Technical Field
The present invention relates generally to an optical system, and more particularly to a compact optical image capturing system for an electronic device.
2. Description of Related Art
In recent years, with the rise of portable electronic devices having camera functionalities, there has been a steady rise in demand for an optical image capturing system. The image sensing device of ordinary photographing camera is commonly selected from a charge coupled device (CCD) or complementary metal-oxide semiconductor sensor (CMOS Sensor). In addition, as advanced semiconductor manufacturing technology enables the minimization of pixel size of the image sensing device, optical image capturing systems are developing fields of high pixels. Therefore, there is an increasing need for suitable optical systems providing high imaging quality.
The conventional optical system of the portable electronic device usually has a two-piece or three-piece lens. However, the optical system needs a larger aperture to take pictures in a dark environment. Conventional large aperture optical systems usually have several problems, such as large aberration, poor image quality at periphery of the image, and are difficult to manufacture. Moreover, substantial distortion often accompanies conventional wide-angle optical system. Therefore, conventional optical systems have up to now not provided the high level optical performance needed.
In particular, an issue persists relating to a need to increase the quantity of light entering the lens and the angle of field of the lens. In addition, there is a need for modern lens having several improved properties, including high pixels, high image quality, small in size, and high optical performance.